As The Old Republic introduces thousands of new elements to the Star Wars Expanded Universe, this article refrains from using "(First appearance)"; instead, the following symbols are used to indicate whether an element originated in a source other than the base game.

A † signifies a character, location, event, etc. originated in another source.

A ‡ signifies a character, location, event, etc. that first appeared in or was first mentioned in Rise of the Hutt Cartel rather than the original game.

A Γ signifies a character, location, event, etc. that first appeared in or was first mentioned in Galactic Starfighter rather than the original game.

A Σ signifies a character, location, event, etc. that first appeared in or was first mentioned in Galactic Strongholds rather than the original game.

A Θ signifies a character, location, event, etc. that first appeared in or was first mentioned in Shadow of Revan rather than the original game.

A Φ signifies a character, location, event, etc. that first appeared in or was first mentioned in Knights of the Fallen Empire rather than the original game.

A Δ signifies a character, location, event, etc. that first appeared in or was first mentioned in Knights of the Eternal Throne rather than the original game.

A strikethrough signifies a character that was present in the game after release but was later removed from the game.

The following are the in-universe representations of the eight class characters: